Tending to flow (5)
I believe the answer is:
runny
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tending to flow</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for runny that I've seen before include "Tending to flow" , "Not set, inclined to spread" , "Like water" , "More liquid than usual" , "Not viscous" .)